Programmable logic controller (PLC) expansion device and PLC control system for displacement sensor

Abstract

The invention discloses a programmable logic controller (PLC) expansion device for a displacement sensor. The PLC expansion device comprises a displacement sensor accessing circuit, a register, a processor for detecting whether position information input by the displacement sensor accessing circuit exceeds limit value information stored in the register and outputting alarm information as well as a communication interface, a limit alarm output circuit and a module working power which are connected with a main PLC controller, wherein the displacement sensor accessing circuit and the register are electrically connected with the processor respectively; and the communication interface and the limit alarm output circuit are electrically connected with the processor respectively. The invention discloses a PLC control system for the displacement sensor. According to the PLC expansion device and the PLC control system for the displacement sensor, the safety protection function of the displacement sensor is improved, and the limit working condition of the displacement sensor can be controlled independently; and control over a safety protection output can be supplied, is stable, and is high in efficiency.

Description

technical field [0001] The present invention relates to the field of programmable control, in particular to a PLC (Programmable Logic Controller, Programmable Logic Controller) expansion device and control system for displacement sensors. Background technique [0002] Displacement sensor (electronic ruler) is a device that can convert linear mechanical displacement into electrical signal, and it has been widely used in many automation equipment, such as plastic molding equipment. In the prior art, the displacement sensor is usually installed on the transmission mechanism of the mechatronics equipment, and performs real-time position feedback on the operating position of the transmission mechanism under the control of the PLC control device. The PLC controller performs continuous motion control by continuously monitoring the position feedback value of the displacement sensor on the device. [0003] Since the smooth operation of the power drive mechanism is related to the saf...

AI Technical Summary

Problems solved by technology

This kind of safety protection method is prone to mechanism crash, displacement sensor pull rod (push rod) pull-off (ejection), etc. security incident

That is to say, the existing security protection methods based on the normal operation of the PLC main controller and the fast enough processing and response speed of the main PLC controller can no longer meet the actual needs of comprehensive protection.

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